As the other two Realtors already mentioned, nothing about what you're saying sounds correct, however, at this time the situation you're mentioning is a legal matter, and, as such, your best answers will come from a qualified real estate attorney in your area.
Typically, payments are not allowed to be made outside of the sales contract. Your Realtor should have discussed this with you. Also, an appraisal does not require the Seller's consent to be completed. If you're saying that the sellers prevented you and the appraiser from entering the home without "bribe" money, well, then that's highly suspect, and I have to ask "why" you, as the buyer, would agree to buy a home when the sellers were so uncooperative.
My suggestion is that you immediately contact an attorney and have him/her help you with this matter. I know it's only small claims court, but without knowing the principles of law, you will be unable to effectively fight this matter in court. If you do not know of any real estate attorneys, you can contact David Van Atta at the offices of Hanna & Van Atta in Palo Alto, or you can speak with Cappy Myers, who is a frequent Real Estate professional here on Trulia at (408) 348-3740.
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